*{padding:0;margin: 0}
        .shake_box {
            background: url(../../img/chanzi2.jpg) no-repeat #1e2020 center center;
            position: fixed;
            top : 0;
            left: 0;
            width  : 100%;
            height : 100%;
        }
        .shakTop,.shakBottom {
            background: #fff;/* background: #282c2d*/
            position : fixed;
            left  : 0;
            width : 100%;
            height: 50%;
        }
        .shakTop    {top    : 0;}
        .shakBottom {bottom : 0;}

        .shakTop span,.shakBottom span{
            background: url(../../img/watuji.jpg) no-repeat;/* 背景图片*/
            position : absolute;
            left: 50%;
            width : 450px;
            height: 254px;
            margin: 0 0 0 -275px;
        }
        .shakTop    span{bottom : 0;}
        .shakBottom span{
            background-position: 0 -254px;
            top : 0;
        }

        .shake_box_focus .shakTop{
            animation        : shakTop 1s 1 linear;
            -moz-animation   : shakTop 1s 1 linear;
            -webkit-animation: shakTop 1s 1 linear;
            -ms-animation    : shakTop 1s 1 linear;
            -o-animation     : shakTop 1s 1 linear;
        }
        .shake_box_focus .shakBottom{
            animation        : shakBottom 1s 1 linear;
            -moz-animation   : shakBottom 1s 1 linear;
            -webkit-animation: shakBottom 1s 1 linear;
            -ms-animation    : shakBottom 1s 1 linear;
            -o-animation     : shakBottom 1s 1 linear;
        }

        /* 向上拉动画效果 */
        @-webkit-keyframes shakTop   {
            0%   {top: 0;}
            50%  {top: -200px;}
            100% {top: 0;}
        }
        @-moz-keyframes shakTop      {
            0%   {top: 0;}
            50%  {top: -200px;}
            100% {top: 0;}
        }
        @-ms-keyframes shakTop       {
            0%   {top: 0;}
            50%  {top: -200px;}
            100% {top: 0;}
        }
        @-o-keyframes shakTop        { 
            0%   {top: 0;}
            50%  {top: -200px;}
            100% {top: 0;}
        }
        
        /* 向下拉动画效果 */
        @-webkit-keyframes shakBottom   {
            0%   {bottom: 0;}
            50%  {bottom: -200px;}
            100% {bottom: 0;}
        }
        @-moz-keyframes shakBottom      {
            0%   {bottom: 0;}
            50%  {bottom: -200px;}
            100% {bottom: 0;}
        }
        @-ms-keyframes shakBottom       {
            0%   {bottom: 0;}
            50%  {bottom: -200px;}
            100% {bottom: 0;}
        }
        @-o-keyframes shakBottom        { 
            0%   {bottom: 0;}
            50%  {bottom: -200px;}
            100% {bottom: 0;}
        }